Apparatus for treating webs



July 30, 1957 F. A. HOLES 2,800,725

APPARATUS FOR TREATING WEBS Filed March 31. 1954 5 Sheets-Sheet 1 FlG.l

INVENTOR. FLOYD A.

w HOLES EL" Fr e.

x Mart; ATTORNEYS July 30, 1957 HQLES 2,800,725

APPARATUS F OR TREATING WEBS Filed March 31. 1954 ts-Sheet 2 FIG. Iw

I iI INVENTOR.

FLOYD A.

y 1957 F. A. HOLES APPARATUS FOR TREATING WEBS 3 Sheets-Sheet 3 FiledMarch .31, 1954 INVENTOR. FLOYD A.l-IOLES ATTORNEYS 2,800,725 APPARATUSson TREATING WEBS Floyd A. Holes, Solon, Ohio, 'assignor, by mesneassignments, to The Dobeckmun Company, a corporation of Ohio ApplicationMarch 31, 1954, Serial No. 420,003

1 Claim. (Cl. 34-452) The present invention relates to ovens forcontinuously heat-treating webs, coated webs or laminated webs composedof various materials such as foils, films, paper, fabric, and the like.

Heretofore, the devices employed for heat-treating or curing webs andlaminated webs or for drying coated webs were subject to one or moreserious disadvantages. Prior devices generally required festooning theweb in a chamber containing heated gases. This type of device, however,not only utilizes the heat very inefficiently but also requires a verylarge chamber so as to give the rapidly moving web sufficient .timewithin the chamber to effect the desired treatment. Another type ofdevice employed a heated surface over which the web passed in directcontact in order to improve heat transfer. However, whenever it becamenecessary to stop the movement of the web, as, for example, when thefeedrolls or take-up rolls needed adjustment or when the coating device,ifsuch were used, needed adjustment, the heat from the heated surfacewould damage or destroy the stationary web.

It is the object and advantage of the present invention that veryefficient heat transfer to the web is obtained,

and yet movement of the web through the oven may .be stopped withoutdamage or destruction of the web. Other objects and advantages will beapparent from the following description of a specific embodiment of theinvention and the drawings therefor, in which:

Figures 1 and 1a illustrate in side elevation, partly broken away, aspecific embodiment of the invention, and

Figure 2 is a cross-section taken along line 2-2 of Figure 1a, the viewshown in Figure 2 being drawn to a larger scale than that of Figures 1and 1a.

The oven, in general, comprises a plurality of heated elements or platesover which the web is passed and means for lowering the heated elementsas a unit out of contact with the web while maintaining the websubstantially in its original position. Thus, the web and the heatedelements can'be separated whenever desired to prevent damage toordestruction of the web, preferably without altering the path of travelof the web between the feed roll and the take-up roll and also withoutnecessarily cooling the heated elements. The path of travel of the webthrough the oven is generally arcuate at all times so as to ensureuniform contact of the web with all of the heated plates when the web isdrawn thereover and so as to provide a substantially uniform distancetherebetween when the plates and web are separated.

With reference to Figure 1, there is provided a feed roll 11 carryingthe web 12. This web is passed over idler rollers 13 and 14, as shown,and is coated with a lacquer or other coating composition adjacent roll15 by any conventional coating device shown generally at 16. A supplypipe 17 for the coating composition is provided as shown. The feed rollsare driven by a motor 18 and conventional chain drives, including anyconventional speed regulator (not shown) such as a speed governorcontrolled by the tension of the web or the diameter of the roll of web12 on the roll 11. The motor 18 may tactthemin this position. However,when 2,800,725 Patented July 30, 1957 also drive the take-11p rolls, aswill be described hereinafter.

It will be understood that the device 16 for applying the coatingcomposition may be replaced by or employed in addition to other devices,such as laminating devices by which two webs may be aflixed together, orby which a web or laminated web may be printed with any desired designor indicia. When a coating composition or printing ink is applied to aweb, the heat treatment is usually employed for drying or setting thecoating composition or for evaporating the solvent from the ink. On theother hand, when a laminating operation is carried out, the subsequentheat treatment may be employed for setting the adhesive between the websor for bonding the laminae together. Also, the heat treatment may beemployed for stretching the webs of certain materials while in a heatedcondition.

When the web 12 leaves the roller 15 it passes over a uficession ofspaced plates .19, which are heated as will be described in greaterdetail hereinafter.

With reference to Figure 1a, the web leaves the oven and is passedbetween tension rollers 20 and 21 which draw the web and maintain itunder tension as it passes through the oven. The web then passes overidler roller 22 to take-up roll 23. As mentioned above, the take-up roll23 may be driven by the motor 18 (Figure 1) by means of drive shaft 24and conventional chain drives. The speed of the take-up roll may beregulated by any conventional device (not shown), such as a speedgovernor controlled by the tension of the web .or the diameter of theroll of web 12 on the take-up roll 23.

As will be seen in Figures 1 and la, the web 12 passes through the ovenover plates 19, which are supported by transverse V-shaped supports 26secured at their ends to the frame 27. Heating elements 28, which willbe described in greater detail hereinafter, for heating the plates 19are disposed between the V-shaped supports 26 and are mounted under theplates 19 and on the frame 27.

Pneumatic or hydraulic jacks 29 and 29, or other type of liftingdevices, are disposed between the ends of the oven and support the frame27 by transverse beams 29". Thus, the frame .and the parts supportedthereby, i. e., the heating elements 28, the V-shaped supports 26 andthe plates 19, can be raised .or lowered as desired by operating thelifting devices 29 and 29' in synchronism.

When the frame 27 is in its uppermost position, as shown-in Figures 1and 1a, transverse members 30, which are attached to a stationary frame31 (see Figure 2) are located between andjust below the plates 19 andwithin the V of the supports 26, so that the web does not con- Vtheframe 27 is lowered, thus lowering the plates 19, the members 30support the'webin substantially the same position as when the web 12 issupported by the plates 19.

A longitudinal hood 32 may be disposed over the oven and may extend downeach side thereof. Passages or ducts 33 lead from the top of the hood 32to vent heating gases, as will be described hereinafter.

The heating elements 28, as shown in the drawings, comprise gas burnersextending transversely of the oven and mounted on the frame 27. As shownin Figure 2, the burners 28 are connected to one or more manifolds 38which, in turn, may be connected to one or more flexible connections 39to a source of fuel. Although gas burners have been illustrated in thedrawings, it will be clear to anyone skilled in the art that other typesof heating elements, such as oil burners or even electrical units, canbe used if desired. While two burners 28 are shown located below eachplate 19, it will be understood that a greater or smaller number ofburners can be used if desired.

At the ends of each of the plates 19, a baffle wall 25 extendsdownwardly between the legs of adjacent V-shaped supports 26, thusforming an enclosed heating chamber which is open at the bottom toreceive the combustion gases from the burners. The gases escape from thesides of the heating chambers and rise around the side edges of theplates 19 to the hood 32 andare vented through ducts 33. v a

Stabilizing devices are located at various points along the length ofthe oven. Such devices are shown at 34 and 35 in Figures 1 and 1a.Corresponding devices, such as the one shown at 35 in Figure 2, arelocated on the opposite side of the oven. Also, as shown best in Figure2, stabilizing ,device 36 is located centrally of the oven adjacentlifting device 29. A companion stabilizer 36' is located similarlyadjacent 'device29', as seen in Figure 1. Since each of the stabilizersoperates in a similar manner, the following description will relate tothe stabilizer shown at 36 in Figure 2. A flexible linked gear chain 40is attached at its ends to stationary, fixed points at 41 and 42 whichdo not move with the frame 27. Two spaced idler sprocket wheels 43 and44 are rotatably mounted on the movable frame 27, the chain 40 passingaround the wheels 43 and 44 as shown. When the frame 27 is raised orlowered, the wheels 43 and 44 are correspondingly raised or lowered. Anytendency for the frame to tilt about its longitudinal axis in aclockwise direction is prevented by the stabilizer 36, since suchtilting would tend to increase the length of the path of the chain 40from point 42 over the wheels 43 and 44 to the point 41. However, itwill be seen that stabilizer 36, as viewed in Figure 2, will not preventtilting of the frame in a counter-clockwise direction, since suchmovement of the axes of the wheels 43 and 44 tends to shorten the pathof the chain 40. For this reason, the companion stabilizer 36' shown inFigure 1 is arranged as a mirrorimage of the one shown in Figure 2, i.e., the lower fixed point of the chain is on the right side instead ofthe left, and the upper fixed point is on the left side instead of theright; the chain passes over the right-hand sprocket wheel and under theleft-hand sprocket wheel. Thus, stabilizer 36' will prevent the framefrom tilting in a counter-clockwise direction but will not preventtilting in a clockwise direction. Thus, to improve the stabilizingaction of the devices, they may be coupled so as to act together andprevent tilting in either direction. To obtain this result, one of thesprocket wheels, say wheel 43, may be coupled, as, for example, by theshaft 45 (see Figures 1 and 1a), to the left wheel of stabilizer 36', i.e., the wheel under which the sprocket chain passes. In like manner, thedevice 35 may be coupled to the device 35 (see Figure 2) by a shaft 46,shown broken away for simplicity, and the device 34 may be coupled tothe corresponding device (not shown) on the opposite side of the oven.

In operation, a web 12 is passed from the feed roll 11, over rolls 13,14 and 15, then over and in contact with the spaced plates 19, throughthe oven to rolls 20 and 21, idler roll 22 and take-up roll 23. Theplates 19 are heated by the heating elements 28 to provide the desiredheat treatment of the web. The combustion gases from the heatingelements 28, if combustible fuel is employed, with or without any vaporsfrom the web, pass into the hood 32 and are vented through ducts 33.

When it becomes necessary to stop the web in order to prevent damage ordestruction thereof, jacks 29 and 29 are operated to lower thelongitudinal frame 27 and thus lower the heated plates 19 and heatingelements 28. The transverse members 30 are not lowered, and the web 12will be supported thereby as soon as the plates 19 have moved below themembers 30. Thus, the web and the heated plates are separated so as toprevent damage to the web. The heating elements 28 may be left on, ifdesired, particularly when the heat-treating of the Web is expected tobe resumed in a short time.

When the frame 27 is lowered, stabilizers 34, 35 and 36 and thestabilizers to which they are respectively connected, as explainedabove, operate to prevent tilting of the frame 27 about a transverseaxis or about a longitudinal axis.

As soon as heat-treating of the web is to be resumed, the jacks 29 and29 raise the frame 27 until the plates 19 pass above the elements 30 andagain support the Web along its length.

Although the present invention has been described with particularreference to the drawings, it will be understood that variousmodifications will occur to those skilled in the art, and it is intendedthat such modifications which come within the scope of the appendedclaims be covered thereby.

What is claimed is:

' Means for heat-treating a movable Web comprising an oven structure,said oven structure comprising a frame and a hood movable relative toeach other, and perpendicular to the length of said oven structure, aplurality of heated plates supported by said frame in longitudinallyspaced relationship and arranged on said frame to support, in normaloperation, a web moved through said oven, means to heat said plates, aplurality of longitudinally spaced transverse members fixed relative tosaid hood and normally located between said plates along the path oftravel of said web, and means to move said frame and hood relative toeach other so that said transverse elements will support said web awayfrom said plates.

References Cited in the file of this patent UNITED STATES PATENTS1,229,101 Linfoot June 5, 1917 1,266,735 White May 21, 1918 1,360,323Sass Nov. 30, 1920 1,432,302 Reed Get. 17, 1922 1,571,282 Leculier Feb.2, 1926 1,710,442 Warshaw Apr. 23, 1929 1,924,100 Barker Aug. 29, 19332,646,968 Curtis July 28, 1953

